This is the 'Graduator' of a WAG-7 located in the HT compartment. A graduator is an equipment through which the windings of the Main Transformer are electrically joined with the primary transformer with the help of CGR 1-2-3 contactors, RGR(Graduator resistance) & RPGR(Graduator protective resistance).
Sachin Buddhisagar (buddhisagarsachin at gmail.com)